Many people know that ambergris is a rare substance produced by whales, which is added to perfume. But do you know it needs to age for years in order to become perfume-worthy? Or that it's filled with squid beaks? Find out what makes ambergris smell so wonderful.

Top image: The capture of a sperm whale in the Pacific Ocean, 1835. Engraved, printed and coloured by J. Hill, from a sketch by Cornelius B. Hulsart. (Photo by Hulton Archive/Getty Images)

There are plenty of distasteful facts about ambergris. There's the fact that it was one of the reasons sperm whale hunting was such a profitable activity. There's the fact that it smells like cow dung when it's fresh. Perhaps the most unsettling, though, is that no one is entirely sure which whale hole it comes out of. There are three candidates, and each of them is distateful. Ambergris got the reputation of being 'whale vomit,' probably because it was the least unappealing choice. More likely, scientists say, it comes out the back end of the whale, judging by the smell.

The reason why most no one has managed to see a whale discharging its valuable cargo is because the substance comes from sperm whales, which spend most of their time well under the waves, in deep water, hunting giant squid. When dead sperm whales wash up on shore, scientists find squid beaks lodged in their stomach. They also find many beaks in ambergris. The fatty, indigestible substance is probably made by the whale's intestines specifically to trap these beaks and give them a smooth ride out of the whale.

Little-known fact; almost all whale poop floats. The nutrients in it provide for a great deal of shallow-water marine life. Ambergris isn't known to be food for anything, but it too floats along the waves. The whale excretes hundreds of pounds at a time, but exposure to surf and the fact that ambergris is soft when it's first excreted break the lumps up. After years in salt water, its cow-dung-like smell gives way to a smooth, rich odor. The molecules of ambergris associate well with fats, and they form attachments to the scents that are put in perfume. The ambergris not only provides its own smell to round out fragrances, its heavy particles anchor the scents in a perfume, preventing them from going to vapor and keeping the perfume from fading too quickly.

The rarity of it, and the lengths it took to obtain it, made ambergris the subject of legend. It was, and sometimes still is, used as an aphrodisiac, put in food, or burned as incense. It even used to be prescribed by ancient doctors to cure anything from migraines to epilepsy. It makes an appearance in plenty of fantasy fiction as well. H2O: Just Add Water has ambergris as a supposed mermaid aphrodisiac. In The Darkangel Trilogy, by Meredith Ann Pierce, ambergris has the power to heal any wound.

Today ambergris has a modern allure; money. It can fetch five thousand dollars a pound. But there are plenty of disgusting, dark, waxy lumps floating in the sea, and they are more likely to be decayed animal life than ambergris. How to tell? For one thing, ambergris is almost exclusively found in the southern hemisphere. No one knows why.

But if you should come across a lump there are a couple of basic tests that should separate ambergris from any other lump of yuck. A heated needle should melt ambergris immediately into a sticky, stringy black goo, some of which should stay on the needle. When the needle is heated again, the black goo should turn to white smoke. A small scraping of the substance should dissolve in warm methyl alcohol, and when the liquid cools, the sample should form a crystalline structure.

These basic tests should set you on the right path, but the substance will need a quick trip to the lab to confirm its properties and quality. Once you've done all of that, well, if you're an American citizen what you'll need is a trip out of the country and perhaps a reliable fence. Laws regarding the buying and selling of parts, even discarded, of endangered species, prohibit the sale of ambergris. But don't worry, you'll have plenty of time to find a way to cash in. One of the most famous cases of accidental discovery of ambergris involved two sisters who kept a four-pound lump for fifty years as a souvenir. It was even more valuable in year fifty than it was when they first found it. (It didn't cure all wounds, though.)